Measurements and analysis of the SIS-300 dipole prototype during the functional test at LASA

The FAIR facility, under construction at GSI, includes the synchrotron SIS300 (300 Tm rigidity). In order to reach the required high intensities of protons and heavy ions beams, the bending dipole magnets (beam tube diameter aperture 100 mm) have to be pulsed from the injection magnetic field of 1.5 T to the extraction field of 4.5 T at the rate of 1 T/s. The first 3.9 m long model dipole has been built and the tests have been carried out at LASA Lab in 2012. These tests have allowed to assess the performance of the magnet, also in pulsed regime. The performance limitation in fast ramp condition appeared mostly due not only to the ramp rate, but also to the total variation of the current, suggesting an effect due to induced current in the superconducting strands in particular zone of the conductor. The paper illustrates the results of the measurements and presents some models to describe the quench during the ramp of the current.